customizable http endpoint path to metrics

[theliuk]

Is your feature request related to a problem? Please describe

Our platform requires (as a convention) all the services to expose metrics atGET /-/metrics http endpoint.
mongodb-query-exporter exposes the metrics at GET /metrics. It'd be useful to allow the user to choose the path at which the metrics are exposed.

Describe the solution you'd like

A simple configuration parameter, like metricsEndpointPath

[raffis]

@theliuk This is now available in v1.0.0-beta7 (See readme, or cmd help).